In this study, using steady-state electrochemistry at a rotating disk electrode, a deposition mechanism for giant magnetostrictive Fe 1 - xGa x alloys is proposed in which the formation of an adsorbed monovalent [Fe(I)] ads intermediate is determined to be the rate-determining step. In subsequent steps, this intermediate either gets reduced to iron or catalyzes the reduction of gallium by forming an adsorbed [Ga(III)-Fe(I)] ads intermediate. In line with the proposed mechanism, it was experimentally shown that the differences in the mass-transport rates of Fe(II) species determined the thin film composition. Therefore, this study has made possible a controllable and reproducible deposition of Fe 1 - xGa x thin films with compositions in the entire range of interest (15%-30% Ga). As-grown Fe 80Ga 20 thin films were found to have magnetostriction constants of ~ 112 ppm.
Bibliographical noteFunding Information:
This work was supported by the MRSEC Program of the National Science Foundation under Award Number DMR-0819885 and the U.S. Office of Naval Research (Dr. Jan Lindberg) under ONR N000140610530 . Part of the work was done in the UMN Nanofabrication Center and Characterization Facilities under the NSF NNIN Program. We also thank Prof Bill Robbins for measurements of magnetostriction.
- Deposition mechanism
- Giant magnetostrictive alloy
- Rotating disk electrode